The Microstructure and Formability Study on DP Steel of Lightweight Automobile

Abstract:

Dual phase (DP) steel is a high strength steel for auto-panel. In this paper, mechanical property, forming ability, baked-hardening and work hardening properties of high strength steel DP450 are studied by experiments, and compared with those of steel MS6000.And theoretical research on predicting the forming limit of steel DP450 by the NADDRG model. The established mathematic model for relativity is of practical usefulness. Experimental results reveal that the yield strength of steel DP450 is about 7.2% lower than the MS6000,and the break strength increases by 18.9%,while the elongation increases by 19%.The strain hardening exponent of steel DP450 are superior to those of MS6000.The results show that mechanical property of high strength steel DP450 is better than that of MS6000,while forming ability of DP450 is not lower than that of MS6000.And baked-hardening and work hardening properties of steel DP450 are better than those of MS6000.The steel sheet DP450 owned a good forming ability.

• Periodical: Materials Science Forum (Volumes 704-705)
• Pages: 1465-1472
• DOI: https://doi.org/10.4028/www.scientific.net/MSF.704-705.1465
• Online since: December 2011
• Authors: Jin Wu, Da Sen Bi, Liang Chu, Jian Zhang, Yun Tao Li
• Keywords: Dual Phase Steel, Formability, High Strength Low Alloy Steel, Ultralight Automobile

References

[1] KANG Yon-lin: Motor plate quality control and Formability. （Metallurgical Industry Press, China 1999）.

[2] MA Ming-tu, etc: Dual phase steel―the physical and mechanical metallurgy. （Metallurgical Industry Press, China 1998）.

[3] WANG Xian-jin, CUI De-li, TANG Di, WANG Zuo-cheng: Steel, Vol. 27, No. 6（1992）, p.48～52.

[4] S.T. Mileiko: Journal of Materials Science, Vol. 4, No. 11（1969）, p.974~977.

[5] I. Tamura,Y. Tomota, and M. Ozawa. Proc. 3rdInt. Conf. on Strength of Metals and Alloys. Cambridge. 1973, 1: 611~615.

[6] M.F. Ashby. Phil. Mag. 1966, 14: 1157~1178.

[7] M.F. Ashby. ed. A. Kelly and R. B. Nicholson Strengthening Methods in Crystals. 1971, 137 Amsterdam, Elsevier Publishing Co.

[8] WEN Dong-hui: Shanghai Metals, Vol. 27, No. 6（2005）, pp.51-54.

[9] R.A. Grange C.R. Hribal, and L.F. Porter: Metallurgical Transaction A. 1977, 8A: 1775.

[10] Aleksy Konieczny A. Car with dual-phase steel forming Performance Evaluation [J]. World Iron & Steel, 2003, (1): 34-38.

[11] Shi M F, etc. Dual-phase steel and low alloy high strength steel forming properties contrast [J]. World Iron & Steel, 2002, (4): 18-22.

[12] LI Dong-sheng, LI Xue-feng, ZHOU Xian-bin: Metal Forming Technology, Vol. 19, No. 2（2001）, p.14～17.

[13] Oliver S, Fourlaris G, Jones TB. Dual Phase Versus TRIP Strip Steels: a Comparison of Dynamic Properties for Automotive Crash Performance. Materials Science and Technology2006.

DOI: 10.1179/174328407x168937

[14] Huh H, et al. Dynamic Tensile Characteristics of TRIP-Type and DP-Type Steel Sheets for an Auto-Body. International Journal ofMechanical Sciences. (2007).

DOI: 10.1016/j.ijmecsci.2007.09.004

[15] Bleck W, Schael I: Steel Research, Vol. 71, No. 5（2000）, p.173～178.

[16] Fang X F, Dahl W: Materials Research and Advanced Techniques, Vol. 86, No. 1（1995）, p.41～48.

[17] Gusek C O, Bleck W. Dahl W. Modeling of Sheet Metal Testing. Int. Conf. MSMM96. Beijng. (1996).

[18] CHEN Xin-ping, JIANG Hao-min. The prediction and validation of bulging region of forming limit diagram(FLD) of steel sheet[J]. Metal Forming Technology, 2003, 7.

[19] CHEN Xin-ping, WANG Xue-pu. Approach for predicting the limit draw strain of the forming diagram. Metal Forming Technology, 2000, 4.